用 Swift 初始化 UIViewController 的子类？

Question

I'm trying to understand how initialization works in Swift with a subclass of a UIViewController. I thought the basic format was this, but it is throwing errors...

init(nibName nibNameOrNil: String!, bundle nibBundleOrNil: NSBundle!)   {
    //other code
    super.init(nibName: String?, bundle: NSBundle?)
}

Answer 1

You're passing the types, not the variables. You have to pass the variables instead.

init(nibName nibNameOrNil: String!, bundle nibBundleOrNil: NSBundle!)  {
    // Initialize variables.

    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
}

Answer 2

Variables should now be initialized before the call to super.init

init(nibName nibNameOrNil: String!, bundle nibBundleOrNil: NSBundle!)  {

    // Initialize variables.

    super.init() // as required
}

Answer 3

You can initialize with/without parameters.

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

// Default Initializer
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
}

// Initialize with value
init(_ sender: Any?) {
    super.init(nibName: nil, bundle: nil)
}